Emerging collective behaviors observed in biological tissues are largely controlled by the structure of the underlying extracellular matrix (ECM). Notably, cells can deposit aligned fibrous ECM which then acts as a guiding cue for neighboring cells, providing an effective “memory” of the cell trajectories in cell populations and contributing to large correlation lengths in confluent monolayers. Aligned ECM on a surface can be mimicked by synthetic subcellular micro-patterns such as grooves. On the other hand, the spontaneous direction of collective migration can be controlled by the release of a well-defined barrier. In the absence of grooves, the direction of migration is perpendicular to the initial barrier. When the substrate is patterned with microlines making an angle with direction, the collective behavior of the monolayer is then either dominated by the initial barrier direction, by the grooves’ direction, or may result from a compromise. In the same line, other geometries such as a regular array of obstacles defining an “easy axis” at an angle with the migration direction define an energy landscape in which collectively migrating cells may be kinetically locked-in, the corrugation of this energy landscape being tuned by the depth of the micropattern. These experiments will be interpreted with our colleagues from the theory group of the laboratory, shedding light on the behavior of cell populations in complex environments.